1. Field of the Invention
The present invention generally relates to an ergonomically designed seating unit which naturally exercises the body by providing active sitting and, more particularly, to such an ergonomically designed seating unit which employs a fluid-filled, substantially egg-shaped, or ball-shaped seat, which promotes continuous movement of the spine, hips and upper body.
2. Background Discussion
Increasingly, scholars, students and workers are required to spend prolonged periods seated at a learning place, or a workstation. As a result, the potential for back, shoulder and neck problems has considerably increased. This is particularly true when seated in a conventional chair having a rigid seat which, with prolonged use, restricts blood circulation to the legs and does not allow for constant small movements of the spine, hips and arms. These small movements, herein referred to as xe2x80x9cactive sittingxe2x80x9d or xe2x80x9cdynamic sittingxe2x80x9d, are especially beneficial in reducing or preventing pains in the upper body.
Children, while in growth, are especially endangered in this respect, and if not properly seated, can catch permanent damage to their body. To them the principle of xe2x80x9cactive sittingxe2x80x9d applies therefore especially.
It is known to provide conventional students chairs or office chairs with mechanical arrangements for adjusting the seat height, seat position and backrest position. However, such mechanic devices need periodic servicing, are susceptible to breakage and require a good understanding of ergonomics for proper use. While ergonomically correct backrests, when applied to such students or office chairs, can substantially help to reduce back pain, they do not offer a solution to an event more frequent problem caused by tension and pain in the neck and shoulder area.
One proposed solution to address the above-noted problems associated with the conventional rigid-seat chair is the use of a gymnastics ball as a chair. The ball, typically made of plastic, is well suited for exercising, but does not have the required stability for prolonged use as a chair, nor necessarily the proper dimensions essential for office, school and/or other workstation labor. Users typically complain of the need to constantly balance their body on the ball which, if not properly carried out, can lead to accidents, such as falling off the ball.
Other proposed solutions are inflatable chairs, distribution of pressurized fluid to a seating unit, or other improvement to chairs and upholstered furniture. All those proposals offer only a limited horizontal and vertical movement, need air pumps or compressors, do not have castors and are generally not adapted for work at a desk or a table.
Thus, there is a need to provide an improved seating unit that ensures active sitting, optimal sitting position, stability, versatility, variability, mobility and simplicity, yet does not possess the shortcomings of the seating devices presently employed.
It is therefore an object of the present invention to provide an improved seating unit that ensures active sitting, optimal sitting positions for use at a desk, table or workstation and imparts a feeling of stability to the user.
Yet another object of the present invention is to provide an improved seating unit which is adjustable to offer different sitting positions using an easy and simple arrangement which eliminates the need to utilize mechanical or electrical devices, such as hydraulic pistons, levers, air pumps, compressors, or similar devices.
A further object of the present invention is to provide an improved seating unit that can be mounted and dismounted easily and quickly and can thus be transported from one location to another.
Still another object of the present invention is to provide an improved seating unit that is versatile such that the seat of the improved seating unit can be used separately for purposes other than sitting, for example, for playing, gymnastics exercises, relaxation and other exercises.
Another object of the present invention is to provide an improved seating unit that has such a light weight that it can easily be carried from place to place. Yet another object of the present invention is to provide an improved seating unit that can be equipped with an elastic textile cover which adapts itself to the changing size of the seat, thus improving sitting comfort.
An important advantage of the present invention is that the user experiences continuously slight movements of the spine, the hips and the upper body. In this way, pains and tensions caused by a rigid sitting position can be prevented.
Another advantage of the present invention is that the sitting position can be customized and individually tailored for an individuals user by inflating the balloon by mouth, or deflating it by hand, or changing the position of the armrest, or of the sliding base to the balloon, without the need for any mechanical or electric devices. The balloon is held firmly in place by the surrounding connecting elements as soon as the user sits on it and exerts pressure on the seat.
Yet another advantage of the present invention is that it grants the user the known advantages of active and dynamic sitting and at the same time, owing to the rigid frame, the sensation of stability, essential for comfortable, prolonged sitting. Still another advantage of the present invention is that by providing a soft seat, which automatically adjusts itself to fit exactly to the body shape of the user, pains connected with lower body distress are reduced. Since the soft seat has no edges, blood circulation in the legs is not hindered by the soft seat.
Yet another advantageous feature of the present invention is that the elastic cover is fitted tightly to the balloon and, by dividing between the user""s body and the seat surface, reduces perspiration under hot conditions.
Another advantage of the present invention is that the seat surface can be taken out of the seat simply and quickly by hand and used for other purposes, like a toy for children, or gymnastics and other exercises. Afterwards it can be placed back easily in the frame serving as a seat again.
Still another advantage of the present invention is that it is durable and completely free of maintenance.
Yet another advantage of the present invention is that it can be easily and quickly assembled and disassembled into its small and flat components. In this way the transport from one location to another is made very easy and convenient.
These and other objects, advantages and features of tho present invention are achieved, according to one embodiment thereof, by an ergonomic seating unit comprising a main frame having a rigid side frame and a stable bottom frame equipped with a sliding base in which a mobile seat is inserted. The mobile seat can be moved significantly in all directions when the chair is occupied, the mobile seat comprising an inflated ball shaped balloon formed of, for example a rubber or thermoplastic material.
The frame is formed, for example, of steel or other suitable metals and comprises: 1) an oval or U shaped upper frame, which can be surrounded by upholstery, and serves as backrest and armrest, 2) a round or star shaped lower frame equipped with traversal tubes or a sliding base for the seat surface and 3) vertical tubes which connect the upper frame to the lower frame. The whole structure is held together by suitable fasteners, such as for example bolts or screws or the like. An additional flexible backrest, possessing a rectangular or oval shape can be attached to the middle vertical connecting tube. This flexible backrest is also adjustable horizontally and vertically.